I haven't fished it near Bozeman but have fished it in the park and as far north as Taylor's Fork. Excellent fishing, good hatches, hoppers and other terrestrials. Fish aren't super huge (a least not the ones I caught) but are plentiful and spunky.

Its good, not great. Easy access, although this is because 191 (truck traffic) runs parellel to. Beautiful drive, but fast. I managed a few dozen mid-sized browns on a hopper dropper rig in a lazy days fishing. Fun to fish your way from Bozeman to Yellowstone. Its popular so expect rafts and other fisherman.

Bozeman is an hour from the Madison (Ennis area). Here you will find bigger trouts.

Bozeman is a half hour from Livingston. Here you will find bigger trouts and spring creeks (with bigger trouts).

If your stay is long enough, plan to fish more than just the Gallitan but fish the Gallatin. Stop at Troutfitters in Bozeman. http://troutfitters.com/

I lived five miles away for 30 years.Seldom fished it after the first five as Yellowstone and Madison are both within 20 miles.However the part up the canyon[south ] would be a very comfortable place to fish for someone use to Pa. waters.Very pretty up there also.The bigger rivers can be a little intimidating and frustrating for first timers.If you have local friends by all means try them all.plus tribs to the Gallatin can be fun and some really beautiful lakes up the Canyon.you will enjoy-sounds like you will be there for salmon fly hatch.

Visted Montana for the first time back in July. Of the 4 rivers I had a chance to fish, the Gallatin was my favorite. We did very wellcaught lots of hard fighting rainbows and browns and a few cutts in the upper end, most in the 8-12"range but we did catch some larger ones. The best were 2 browns in the 20" range. Beautiful water, highly recommend.

We saw lots of rafters in the lower to middle section canyon sections. They would float through in pods of 10 rafts every 1/2 hour or so. The fish did not seem to mind. My favorite section was the upper portion near the Yellowstone entrance. Very meadowy beautiful area.

Even though the road was nearby I kept looking over by shoulder expecting to see a grizzly charging toward me.

You cant fish into the park without an additional Park License so we didnt bother. We didnt see that many other anglers but I think thats considered crowded by Montana standards.

I spent a little time on it once while driving between the bighorn and yellowstone area.Very pretty stream for sure - but then so is just about any place out west IMO.Caught lots of smallish fish, and we didn't hang around very long. Lots of better streams, that aren't very far away IMO

I bicycled along it from the park to the Bozeman area. Nice river, nice habitat, which is much more readily seen from a bike than a car. Would have loved to have had the time to fish it. My recollection is that parts of it become warm during some summers and it is one of the rivers on which MT requires that all fishing terminate by a certain time of day during those particular summers. Others may be able to fill you in on this.